Injection Moulds and Dies: Choosing the Right Mould for Your Volumes
The mould is the biggest single cost in a moulded or die-cast part, and the right one depends on how many parts you will make over its life. Compare the main mould classes, see where each pays off, and learn how to source tooling.
The short answer
Choose the mould by how many parts it needs to make over its life:
- Prototype (aluminium) moulds for bridge tooling and launches of up to around ten thousand parts.
- Pre-hardened P20 steel moulds for most production parts, from tens of thousands to hundreds of thousands of shots.
- Hardened H13 steel moulds, often multi-cavity, for very high volumes, glass-filled plastics and die-casting dies.
- Your advisor can quote two classes side by side so you can compare mould cost against part price.
Prototype vs production vs high-volume moulds
How the three main classes of injection mould compare on cost, life and part price.
Swipe the table sideways to see every option →
| Comparison | Prototype mouldAluminium | Production mouldPre-hardened P20 steelMost common | High-volume mouldHardened H13 steel |
|---|---|---|---|
| Best for | Bridge tooling, launches and design validation | Most production parts | Very high volumes and abrasive, glass-filled plastics |
| Typical mould life | Up to around 10,000 shots | Hundreds of thousands of shots | A million shots or more |
| Mould cost | Lowest | Medium | Highest |
| Cost per part | Higher, single cavity | Medium | Lowest, often multi-cavity |
| Build time | Shortest | Medium | Longest, heat treatment and more cavities |
| Design changes | Easy to modify | Can be modified | Harder to modify once hardened |
| Ownership | Yours | Yours | Yours |
Ratings are general guidance. Your manufacturing advisor confirms the best option for your drawing.
Which mould gives the lowest cost per part?
Drag the slider to change how many parts the mould will make over its life, and see which mould class gives the lowest cost per part.
Illustrative example for a small plastic part, not real prices. The prototype mould line steps up each time it wears out and has to be replaced.
Cold runner vs hot runner moulds
The runner carries plastic from the machine nozzle to the cavities. How it is built changes both the mould cost and the part cost.
Cold runner
The runner solidifies with the part and is cut off each cycle. Simpler and cheaper to build.
- Lower mould cost and simpler maintenance
- Quick colour and material changes
- Runner scrap is reground or discarded
Hot runner
Heated channels keep the plastic molten up to each gate, so only the part is ejected.
- Little or no runner waste
- Shorter cycles at high volumes
- Higher mould cost and more upkeep
Relative ratings out of 5, for comparison between the two options only.
Where to get injection moulds made for an Australian business
Once you know which class of mould you need, the next decision is who builds it and who runs it.
Swipe the table sideways to see every option →
| Comparison | Local Australian toolmaker | Overseas marketplace | RTech factory-direct |
|---|---|---|---|
| Who builds your mould | The local toolmaker | Whichever supplier takes the job | Our own toolroom |
| Mould price | Typically the highest | Varies by supplier, plus platform margin | Factory-direct, no markup |
| Mould and parts from one supplier | Sometimes; often a separate moulder | Varies by supplier | Yes, built and run in the same factory |
| Freight, customs and duty | Not needed | Often quoted separately | Included, one price to your door |
| Sample approval | First articles at the toolmaker | Varies by supplier | First-article samples measured against your drawing |
| Mould ownership | Usually yours | Often unclear | Yours, stored and maintained for reruns |
| Face-to-face visits | Easiest | Not usually possible | Dedicated advisor in Sydney |
General comparison. Individual suppliers vary.
From part design to approved mould
One price agreed up front, and one manufacturing advisor the whole way.
Send your part design
CAD file with expected annual volume, plastic or alloy, and finish.
Mould design and flow review
Gate position, draft, cooling and ejection reviewed before steel is cut. Mould and part price within 48 hours.
Toolroom build
Cavities are CNC machined and EDM’d in P20 or H13 tool steel, then polished or textured.
Trial shots and approval
First-article samples are measured against your drawing and sent for your approval.
Production and storage
Parts run from your approved mould, which we store and maintain for every reorder.
Injection mould questions
Who owns the injection mould?
You do. When you pay for a mould or die, it belongs to you. We store and maintain it for your repeat runs, and release it to you on request.
How much does an injection mould cost?
It depends on the size and complexity of the part, the number of cavities and the mould steel. Your quote shows the mould price and the part price together, and can compare two mould classes side by side.
How long does an injection mould last?
An aluminium prototype mould typically lasts up to around ten thousand shots. A pre-hardened P20 steel mould lasts hundreds of thousands, and a hardened H13 mould a million or more with normal maintenance.
What is the difference between P20 and H13 tool steel?
P20 is supplied pre-hardened, so it is quicker to machine and suits most production moulds. H13 is hardened after machining, which makes it more wear resistant for very high volumes, glass-filled plastics and die-casting dies.
Do you build die-casting dies as well as plastic moulds?
Yes. Die-casting dies, injection moulds and press tools are built in the same toolroom. See our die casting guide for how die casting compares with other metal processes.
Can my mould be modified after sampling?
Usually, yes. Small changes that remove steel are straightforward. Your advisor will tell you before the build which features are easy to adjust later.
How long does it take to build a mould?
Mould build and sample approval come before production, and the time depends on the size and complexity of the mould. Your quote gives a confirmed date for samples and for delivered parts.
Related guides
Ready to price your mould?
Send your drawing and we will come back with one price delivered duty paid, a lead time and any design notes.